1. a Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Safety Research , 1095 Willowdale Road, Morgantown, WV, 26505–2888, USA
2. b BJC Health Care, Corporate Health Services , St. Louis, MO, 63110, USA
3. c Finnish Institute of Occupational Health , 00250 Helsinki, Finland
4. d Liberty Mutual Research Institute for Safety , Hopkinton, MA, 01748, USA
5. e Johns Hopkins University School of Public Health , Baltimore, MD, 21205, USA
6. f Washington University School of Medicine , St. Louis, MO, 63110, USA